This invention relates to electrostatographic reproduction machines, and more particularly to such a machine including a developer material cartridge having a non-interfering dual-use cartridge sealing device.
Generally, the process of electrostatographic reproduction, as practiced in electrostatographic reproduction machines, includes charging a photoconductive member to a substantially uniform potential so as to sensitize the surface thereof. A charged portion of the photoconductive surface is exposed at an exposure station to a light image of an original document to be reproduced. Typically, an original document to be reproduced is placed in registration, either manually or by means of an automatic document handler, on a platen for such exposure.
Exposing an image of an original document as such at the exposure station, records an electrostatic latent image of the original image onto the photoconductive member. The recorded latent image is subsequently developed using a development apparatus by bringing a charged dry or liquid developer material into contact with the latent image. Two component and single component developer material is commonly used. A typical two-component dry developer material has magnetic carrier granules with fusible toner material adhering triobelectrically thereto. A single component dry developer material typically comprising toner material only can also be used. The toner image formed by such development is subsequently transferred at a transfer station onto a copy sheet fed to such transfer station, and on which the toner material image is then heated and permanently fused so as to form a "hardcopy" of the original image.
One familiar type of development of an electrostatic image is called "two-component development" because it utilizes two-component developer. Two-component developer largely comprises toner material interspersed with carrier material The carrier material is magnetically attractable, and the toner material is, caused to adhere triboelectrically to the carrier material. This two-component developer can be conveyed, by means such as a "magnetic roll," to the electrostatic latent image, where toner material becomes detached from the carrier material and adhere as desired to the electrostatic latent image.
Development of the electrostatic image with developer material results in the generation of waste developer material which is removed and stored in a waste sump disposed within the electrostatographic reproduction machine. A waste sump is designed with one or more openings which allow an auger to deposit waste developer material inside the sump. When full, the waste sump is removed from the electrostatographic reproduction machine. Prior to removal of the waste sump, the openings of the waste sump need to be sealed to minimize spillage of the waste developer material. As disclosed for example in U.S. Pat. No. 5,428,436, it is known to provide a waste sump seal member which attempts to prevent or minimize waste developer particle spillage during removal of the waste sump from the machine. Such a waste sump seal member does so by automatically attempting to seal or reclose a waste sump opening immediately upon withdrawal of a waste toner developer material delivery auger from the waste sump opening.
Typically, the seal member for the waste sump opening as disclosed, is slotted and designed mainly to keep the waste toner from leaking during waste toner delivery into the waste sump. However, it has been found that the slotted seal member leaks toner during harsh shipping movements of the removed waste sump to a distant location for recycling purposes. Consequently, the customer or operator must place the waste sump after removal from the machine, into a bag prior to such shipment. The bags and bagging operation required for this are of course costly and time consuming.
Further, it has been found that such repackaging or bagging is not adequate to prevent waste toner or developer material from spilling out of the waste sump through the slits and into the bag or container, and thus making a mess all over the bagged cartridge or waste sump. The bags, the spilled waste toner and the mess on the sump of course further complicate handling and recycling efforts.
There is therefore a need for a sealing device which automatically preseals or closes a waste sump opening immediately upon withdrawal of the waste auger so that the sump can be moved within and removed from the machine without spilling much of the waste developer material. There is also a need for a sealing device which is easy to use, and which can further seal the waste sump opening against waste developer material spillage even during harsh shipping movements to distant locations for recycling.